On February 21, 2014, the USPTO Trademark Trial and Appeal Board (TTAB) issued a precedential decision in In re Hitachi High-Technologies Corp., clarifying that it is not appropriate for an examining attorney to reference a family of marks in ex parte prosecution but affirming the examining attorney's Section 2(d) refusal to register the applicant's mark based on a likelihood of confusion with one of the previously registered marks (Serial No. 79110412 (February 21, 2014)).

Hitachi filed an application to register the mark OPTICROSS for "liquid chromotography apparatus and parts thereof" in International Class 9. The examining attorney issued a Section 2(d) refusal based, in part, on a likelihood of confusion with seven previously registered marks owned by Optimize Technologies, Inc. All of those marks include the term OPTI, either alone or as a prefix, and in the first office action the examining attorney referred to the seven marks as a family. Following Hitachi's objection to the reliance on a family of marks, the examining attorney did not include the reference in later office actions. The final refusal includes a specific retraction of the reference. Hitachi appealed the final refusal.

Although the refusal was not based on the family of marks, the TTAB took the opportunity to clarify that it is not appropriate for a trademark examiner to reference a family of marks when evaluating registrability because:

Turning to whether any of Optimize's registrations on its own provided a basis for a Section 2(d) refusal, the TTAB found the OPTI registration to be the most relevant to the du Pont analysis (In re E. I. du Pont de Nemours & Co., 476 F.2d 1357 (CCPA 1973)). Weighing the pertinent factors, the TTAB found a likelihood of confusion between the OPTICROSS and OPTI marks.